Morphological characterization and response of spider plant (cleome gynandra l.) to npk fertilizer rates and deflowering

Abstract

Spider plant (Cleome gynandra) is among traditional leafy vegetables whose consumption is increasing in Kenya. Characterization of spider plant ecotypes has not been exclusively done even though a collection exists at the national museums of Kenya. Production of spider plant as a vegetable is constrained by low leaf yields resulting from lack of improved planting materials and a short vegetative phase of the plant. The objective of this study was to morphologically characterize 36 spider plant ecotypes and to investigate the effect of various NPK (17:17:17) fertilizer rates and deflowering on leaf yield and extension of the vegetative phase of spider plant. The study was conducted at the Horticulture Training Field three of Egerton University, Njoro for two seasons. In the morphological characterization experiment a 6 × 6 Lattice square design with seven replications and 42 blocks was used. Data was collected on days to first emergence, stem, petiole and main vein pigmentation, number of primary branches per plant, days to 1st, 50% and 75% flowering, flower colour, number of pods per plant, seed yield, 1000 seed weight, leaf yield and dry leaf weight. In the NPK and deflowering experiment a 52 factorial arrangement in a Randomized Complete Block Design (RCBD) with 10 treatments and three blocks was used. Data was collected on days to flowering, number of primary branches, plant height, fresh leaf yield, number of harvesting weeks and dry leaf weight. Results in the characterization experiment indicated that ecotypes took six to eight days to first emergence. In terms of stem, petiole and main vein pigmentation, four plants types were identified based on colour combinations amongst the 36 ecotypes studied: green stems - green petioles and green main vein; purple stems - purple petioles and purple main veins; green stems - purple petioles and purple main veins and purple stems - green petioles and green main veins. White and purple flowers were observed among the ecotypes. The best ecotype was IP8 in terms of fresh and dry leaf weight and number of primary branches compared to the other ecotypes. The hierarchical cluster analysis of the qualitative traits done using Unweighted Pair Group Method of Arithmetic Averaging (UPGMA) generated using DARwin software version 5.0 revealed two major clusters (cluster I and II) with cluster II forming two sub clusters(IIA and IIB). In the crop nutrition and deflowering study, the application of 300 kg NPK ha -1 in combination with deflowering gave the highest fresh leaf yield, leaf dry weight and extended the harvesting duration by four weeks when compared to the control. The number of days to flowering was not influenced by fertilizer rates. Deflowered plants produced significantly higher numbers of primary branches than non-deflowered treatments. It is concluded that morphological diversity is evident in spider plant ecotypes and that deflowering in combination with NPK fertilization significantly increases vegetable yield by extending spider plant’s vegetative phase.